Different linguistic varieties are assigned market values and various prices that are either positive or negative.
The highest market values are assigned to varieties that are rare and desirable in the marketplace.
[3] Linguistic exchange exists on three main levels:[3] On the standard linguistic market, standard languages usually enjoy more value due to the high overt prestige associated with them while on linguistic markets that value non-standard varieties, vernaculars can also enjoy a higher value.
[6] Many researchers have attempted to create new indices to represent the economic parallel that exists within the field of linguistics.
David Sankoff and Suzanne Laberge developed an index to specifically measure how speakers' activity within the linguistic market is related to the speakers' knowledge or application of the legitimate speech for the market.